# -*- coding: UTF-8 -*-
from typing import List
from leetcode_helper import TestcaseHelper, SolutionBase, ListNode, array_to_list, list_to_array, Stack


class Solution(SolutionBase):
    # 解题的方法，命名和Leetcode的保持一致即可
    def reverseKGroup(self, head: ListNode, k: int) -> ListNode:
        dummy = ListNode()
        curr_head = ListNode()
        curr_head = dummy

        stack = Stack()
        while head:
            if stack.size() < k:
                stack.push(head)
            else:
                while stack.size() > 0:
                    node = stack.pop()
                    node.next = None
                    curr_head.next = node
                    curr_head = curr_head.next

                stack.push(head)

            head = head.next

        if 0 < stack.size() < k:
            for i in range(0, stack.size()):
                data = stack.data[i]
                data.next = None
                curr_head.next = data
                curr_head = curr_head.next
        elif stack.size() == k:
            while stack.size() > 0:
                node = stack.pop()
                node.next = None
                curr_head.next = node
                curr_head = curr_head.next

        return dummy.next


if __name__ == '__main__':
    solution = Solution()

    # 按照leetcode的题目说明，将基本的test case填入
    # 每条case的最后一个元素是正确的结果，即期待的结果
    # 使用元组来保存输入的数据，期待的结果
    testcases = [
        ([1, 2], 2, [2, 1]),
        ([1, 2, 3, 4, 5], 3, [3, 2, 1, 4, 5]),
        ([1, 2, 3, 4, 5], 1, [1, 2, 3, 4, 5]),
        ([1], 1, [1])
    ]

    for case_item in testcases:
        # 获取测试用的case和期待的执行结果

        input1 = case_item[0]
        input2 = case_item[1]

        expect = case_item[len(case_item) - 1]

        exec_result = solution.reverseKGroup(array_to_list(input1), input2)

        # 判断执行结果，输出提示信息
        check_result = solution.check_result(expect, list_to_array(exec_result))
        TestcaseHelper.print_case(check_result, case_item, exec_result)

